KR20020075879A - Photo-curable composition and the cured products - Google Patents

Abstract

The present invention relates to a photocurable composition comprising (A1) zirconium oxide particles or composite oxide particles comprising zirconium and (B) a compound having two or more polymerizable unsaturated groups in a molecule,

The composition is substantially free of photo-radical polymerization initiators and relates to a cured product prepared by curing the photocurable composition.

Description

Photocurable compositions and cured products {PHOTO-CURABLE COMPOSITION AND THE CURED PRODUCTS}

In a composition suitable for the above-described purpose, which has been developed and used to date, a composition cured by light (photocurable composition) or a composition cured by electron beam (electron beam curable composition) has recently been widely used for high productivity and other reasons. have. In order to irradiate the composition quickly and sufficiently to cure light, it is essential to use photo-radical initiators for photo-radical polymerization systems and photo-cationic initiators for photo-cationic polymerization systems.

For example, Japanese Patent Publication No. 55307/1987 discloses a photocurable coating composition comprising an acrylate and colloidal silica particles whose surface is modified by methacryloxy silane. As a photo-radical initiator, α, α-diethoxyacetophenone is used. A feature of the coating is to improve the performance of the coating (eg scratch resistance, abrasion resistance, etc.) by treating the surface of the silica particles with a particular organosilane under certain conditions.

However, despite some improvements such as scratch resistance, abrasion resistance, etc., the photocurable composition (coating material) to which the particles are added does not volatilize part of the photo-radical initiator during curing by light, improper curing due to contamination of the lamp, productivity Problems such as the reduction of.

Problems to be Solved by the Invention

The present invention has been completed in connection with the problems described above, and has excellent coating properties, as well as a photocurable composition capable of forming a coating material having high hardness and high refractive index with high productivity without being affected by lamp contamination. It is also an object to provide a cured product prepared from the photocurable composition.

Means for solving the above problem

Conventionally, photo-radical initiators are essential for curing a photocurable composition comprising a compound having a polymerizable unsaturated group. The inventors of the present invention have conducted extensive research to achieve the above object, and surprisingly found that the problem can be solved by adding a photocurable composition comprising:

(A1) zirconium oxide particles or composite oxide particles containing zirconium with other metals

(B) a compound having two or more polymerizable unsaturated groups in a molecule

The composition is substantially free of photo-radical polymerization initiators.

The present invention relates to a photocurable composition and a cured product made from the photocurable composition. In particular, the present invention exhibits excellent coating properties and is suitable for plastics (polycarbonate, polymethacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine resin, triacetyl cellulose resin, ABS resin, AS resin, norbornene resin, etc.) It relates to photocurable compositions capable of forming coatings having high hardness and high refractive index on the surfaces of various substrates such as metals, wood, paper, glass, and slate, as well as cured products made therefrom. The photocurable compositions and cured products include, for example, protective coatings that prevent stains or scratches in plastic optical components, touch panels, film-like liquid crystal components, plastic containers or floorings, artificial marbles used as wall materials and architectural interior finishes; It is suitable for applications such as adhesives of various substrates, sealants and excipients for printing inks.

The photocurable composition and the cured product thereof of the present invention will be described in detail.

Photocurable composition

The photocurable composition of the present invention is a composition comprising oxide particles (A1) and compound (B), and substantially free of photo-radical polymerization initiator (the composition is hereinafter referred to as "first composition"). .

Another photocurable composition of the present invention is a composition comprising reactive particles (A) and compound (B), and substantially free of photo-radical polymerization initiator (the composition is hereinafter referred to as "second composition"). .

The photocurable composition of the present invention may further comprise (C) an organic solvent (hereinafter referred to as "organic solvent (C)").

1.First Composition

Each component for the first composition is described in detail below.

(1) oxide particles (A1)

Oxide particles (A1) used in the present invention are zirconium oxide particles or composite oxide particles containing zirconium.

Examples of the oxide particles (A1) are zirconia particles, zirconium-cerium composite oxide particles and zirconium-titanium-tin composite oxide particles. The compounds can be used individually or in combination of two or more. The oxide particles (A1) are preferably in the form of a powder or a solvent dispersion sol. When the oxide particles are in the form of dispersion, the organic solvent is a preferred dispersion medium from the viewpoint of mutual solubility and dispersibility with other components. Examples of the organic solvent include alcohols, for example methanol, ethanol, isopropanol, butanol and octanol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Esters such as ethyl acetate, butyl acetate, ethyl lactate and γ-butyrolactone, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; Ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; Aromatic hydrocarbons such as benzene, toluene, xylene; And amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. Preferably, one or more of the organic solvents of the group comprising methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene and xylene are used.

The number average particle diameter of the oxide particles (A1) is 0.001 µm to 2 µm, preferably 0.001 µm to 0.2 µm, more preferably 0.001 µm to 0.1 µm. If the number average particle diameter is larger than 2 mu m, the transparency of the cured product and the surface state of the coating material tend to be impaired. Moreover, various surfactants and amines can be added to improve the dispersibility of the particles.

Examples of commercially available products of the oxide particles (A1) are toluene dispersions of zirconia particles such as "HXU-110JC" manufactured by Sumitomo Osaka Cement Co., Ltd. and HIT- manufactured by Nissan Chemical Industries, Ltd. There are zirconium-titanium-tin composite oxide particles such as 30M.

The shape of the oxide particles (A1) may be spherical, hollow, porous, rod, plate, fibrous or amorphous, with a spherical shape being preferred. The specific surface area of the oxide particles (A1) measured by the BET method using nitrogen is preferably 10 to 1000 m 2 / g, more preferably 100 to 500 m 2 / g. The oxide particles (A1) may be used in the form of a dry powder or in the form of a dispersion in water or an organic solvent. For example, a dispersion of fine particles of oxide known in the art may be used as the solvent dispersion sol of the oxide. The use of a solvent dispersing sol of oxide is particularly preferred in applications where good transparency of the cured product is desired.

The oxide particles (A1) are added in an amount of 10-95 wt%, preferably 65-90 wt%. Less than 10 wt%, a product with a high refractive index cannot be obtained; If it is 95 wt% or more, the film forming ability of the cured product is not suitable. Here, the amount of the oxide particles (A1) means the amount of the solid component, when the oxide particles (A1) is used in the form of a solvent dispersion sol does not include the amount of the solvent.

(2) Compound (B)

Compound (B) used in the first composition is a compound having two or more polymerizable unsaturated groups in the molecule. The compound (B) is preferably used to increase the film forming ability of the composition. The compound here is not particularly limited in the form of the compound as long as it has two or more polymerizable unsaturated groups, more preferably a compound having three or more polymerizable unsaturated groups. Compounds such as (meth) acrylic acid esters and vinyl compounds may be provided as examples, with (meth) acrylic acid esters being more preferred.

The following compounds may be provided as specific examples of the compound (B) used in the present invention:

Examples of (meth) acrylic acid esters include trimethylolpropane tri (meth) acrylate, trimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipenta Erythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerol tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (Meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and bis (2-hydroxyethyl) isocia Rate di (meth) acrylate; As well as said (meth) acrylate, oligoester (meth) acrylate, oligoether (meth) acrylate, oligourethane (meth) acrylate and oligoepoxy (meth) having two or more (meth) acryloyl groups in the molecule The acrylates are ethylene oxide or propylene oxide addition poly (meth) acrylates. Among the above, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra Most preferred is (meth) acrylate.

Examples of vinyl compounds are divinylbenzene, ethylene glycol divinyl ether, diethylene glycol divinyl ether and triethylene glycol divinyl ether.

Examples of commercially available products of compound (B) include the trade names Aronix M-400, M-408, M-450, M-305, M-309, M-310, M-315, M-320 , M-350, M-360, M-208, M-210, M-215, M-220, M-225, M-233, M-240. M-245, M-260, M-270, M-1100, M-1200, M-1210, M-1310, M-1600, M-221, M-203, TO-924, TO-1270, TO- 1231, TO-595, TO-756, TO-1343, TO-902, TO-904, TO-905 and TO-1330 (manufactured by Toagosei Co., Ltd.); KAYARAD D-310, D-330, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN-2475, SR-295, SR-355, SR-399E , SR-494, SR-9041, SR-368, SR-415, SR-444, SR-454, SR-492, SR-499, SR-502, SR-9020, SR-9035, SR-111, SR -212, SR-213, SR-230, SR-259, SR-268, SR-272, SR-344, SR-349, SR-601, SR-602, SR-610, SR-9003, PET-30 , T-1420, GPO-303, TC-120S, HDDA, NPGDA, TPGDA, PEG400DA, MANDA, HX-220, HX-620, R-551, R-712, R-167, R-526, R-551 , R-712, R-604, R-684, TMPTA, THE-330, TPA-320, TPA-330, KS-HDDA, KS-TPGDA, KS-TMPTA (manufactured by Nippon Kayaku Co., Ltd.); Light acrylate PE-4A, DPE-6A, DTMP-4A (manufactured by Kyoeisha Chemical Co., Ltd.).

The amount of compound (B) used in the first composition is preferably 5-90 wt%, more preferably 10-35 wt% relative to 100% of the composition (total amount of oxide particles (A1) and compound (B)) to be. When the amount of compound (B) is less than 5 wt%, the film forming ability of the cured product is not suitable; If it is 90 wt% or more, a product having a high refractive index is not obtained.

If desired, compounds having one polymerizable unsaturated group in the molecule can be used in the compound (B) as well as the first composition.

(3) photo-radical initiator

The composition of the present invention is substantially free of photo-radical initiators.

However, the addition of the photo-radical initiator in an amount of 1 wt% or less, preferably 0.1 wt% or less is acceptable because it does not impair the effects of the present invention. If the composition comprises a photo-radical initiator, this is the case when the curing is insufficient due to contamination of the lamp or the productivity decreases while curing the composition.

(4) solvent (C)

The first composition of the photocurable composition may comprise an organic solvent (C) if necessary.

There is no particular limitation, but a solvent such as that used as the dispersion medium for the solvent dispersion sol of the oxide particles (A1) may be used as the organic solvent (C).

The amount of the organic solvent (C) added to the composition is preferably 10-10,000 parts by weight, more preferably 25-1,000 parts by weight based on 100 parts by weight of the composition (total amount of the oxide particles (A1) and the compound (B)). It is wealth. If less than 10 parts by weight, the composition is impaired storage stability, if more than 10,000 parts by weight, it is difficult to form a coating having a desired thickness.

2. Second Composition

The second composition is the same as the first composition except for using the reactive particles (A), which is an organic compound (A2) having a polymerizable unsaturated group instead of the oxide particles (A1) of the first composition (hereinafter, "Organic compound (A2)") and oxide particles (A1). The method for preparing the reactive particles (A) is described below.

(1) oxide particles (A1)

Oxide particles (A1), such as those used in the first composition (A1), are used in the second composition.

(2) an organic compound (A2)

The organic compound (A2) used in the second composition is a compound having an intramolecular polymerizable unsaturated group, preferably a specific organic compound comprising a group represented by the following general formula (1):

Further, the organic compound is preferably a group represented by [-OC (= O) -NH-] and a group represented by [-OC (= S) -NH-] or [-SC (= O) -NH-]. In particular, the organic compound (A2) has a silanol group or a group forming a silanol group by intramolecular hydrolysis.

(i) polymerizable unsaturated groups

There is no specific restriction | limiting in the polymerizable unsaturated group contained in organic compound (A2). Acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, cinnamoyl group, maleate group and acrylamide group may be provided as suitable examples.

The polymerizable unsaturated group is a structural unit for carrying out addition polymerization with active radicals.

(ii) a group disclosed by Formula 1

[-XC (= Y) -NH-] of Formula 1 included in the second organic compound (A2) has six forms, in particular, [-OC (= O) -NH-], [-OC (= S) -NH-], [-SC (= O) -NH-], [-NH-C (= O) -NH-], [-NH-C (= S) -NH-], and [-SC (= S) -NH-]. The groups can be used individually or in combination of two or more. Among the above, the combination of the [-OC (= O) -NH-] group and [-OC (= S) -NH-] and [-SC (= O) -NH-] has excellent thermal stability. It is preferable from the standpoint of maintaining.

[-XC (= Y) -NH-] group of Chemical Formula 1 generates mild bonding force by hydrogen bonding between molecules, and has curing properties such as excellent mechanical strength, good adhesion to a substrate, and good heat resistance. Provide the product.

(iii) silanol groups or groups which form silanol groups by hydrolysis

The organic compound (A2) is preferably a compound having a silanol group (hereinafter referred to as "silanol group-containing compound") or a compound which forms a silanol group by hydrolysis (hereinafter referred to as "silanol group-forming compound"). There is). Examples of silanol group forming compounds are compounds having a Si atom which is at least partially substituted with an alkoxy group, an aryloxy group, an acetoxy group, an amino group or a halogen atom. Preferred silanol group forming compounds are alkoxysilyl group-containing compounds or acyloxysilyl group-containing compounds.

The silanol group-forming site of the silanol group or silanol group-forming compound is a structural unit bonded to the oxide particles (A1) by a condensation reaction by condensation reaction or hydrolysis.

(iv) preferred embodiments

Compounds represented by the following formula (2) are preferred specific examples of the organic compound (A2).

(In Formula 2, R ¹ and R ² is a hydrogen atom or an alkyl group having 1-8 carbon atoms, such as a methyl group, ethyl group, propyl group, butyl group or octyl group, or an aryl group having 6-12 carbon atoms, eg For example, a phenyl group or a xylyl group; R ³ is a divalent organic group having C ₁ -C ₁₂ aliphatic (which may be linear, branched or cyclic structure) or aromatic structure; R ⁴ is a divalent organic group , Usually selected from divalent organic groups having a molecular weight of 14 to 10,000, preferably 76 to 500; R ⁵ is (n + 1) is an organic group, preferably linear, branched or cyclic saturated or unsaturated Selected from the group consisting of hydrocarbon groups; R ² , R ³ , R ^4, and R ⁵ include heteroatoms such as, for example, O, N, S, and P; Z represents an intramolecular crosslinking reaction in the presence of a reactive radical. M is a monovalent organic group having an intramolecular polymerizable unsaturated group; m An integer from 1-3; n is preferably an integer of 1 to 20, more preferably an integer of 1 to 10, more preferably an integer of 1 to 5.

Examples of the group represented by [(R ¹ O) _m R ² _3-m Si-] include trimethoxy silyl, triethoxy silyl, triphenoxy silyl, methyldimethoxy silyl, dimethylmethoxy sil A diary or the like may be provided. Among the above, a trimethoxy silyl group, a triethoxy silyl group, etc. are preferable.

Examples of the organic group (Z) include acryloyl group, methacryloyl group, vinyl group, propenyl group, butadienyl group, styryl group, ethynyl group, cinnamoyl group, malate group and acrylamide group.

The second organic compound (A2) and the reactive particles (A) used in the second composition can be prepared, for example, by the method described in Japanese Patent Application Laid-Open No. 100111/1997.

The amount of the organic compound (A2) bonded to the oxide particles (A1) is preferably 0.01 wt% or more relative to 100 wt% of the reactive particles (A) (total amount of the oxide particles (A1) and the organic compound (A2)), More preferably at least 0.1 wt%, particularly preferably at least 1 wt%. When the amount of the organic compound (A2) bonded to the oxide particles (A1) is less than 0.01 wt%, the dispersibility of the reactive particles (A) in the resulting composition is poor, and the transparency and scratch resistance of the cured product are not sufficient. . Furthermore, the ratio of the oxide particles (A1) as a raw material in the production of the reactive particles (A) is preferably 5-99 wt%, more preferably 10-98 wt%.

The reactive particles (A) are added to the composition in an amount of 10-95 wt%, preferably 65-90 wt%. Less than 10 wt%, a product with a high refractive index cannot be obtained; If it is 95 wt% or more, the film forming ability of the cured product is not suitable.

The amount of oxide particles (A1) in the reactive particles (A) is preferably 65-90 wt% relative to 100 wt% of the composition.

The amount of the reactive particles (A) herein means the amount of the solid component, and the amount of the solvent is not included when the reactive particles (A) are used in the form of a solvent dispersion sol.

3. How to coat the composition

The composition of the present invention is suitable as a coating material. Plastics (polycarbonate, polymethylene acrylate, polystyrene, polyester, polyolefin, epoxy, melamine, triacetyl cellulose, ABS, acrylonitrile-styrene resin, norbornene resin, etc.), metal, wood, paper, glass, slate, etc. It may be provided as an example of the substrate covered with this composition. The substrate may be an object in the form of a film or in a three-dimensional shape. Conventional coating method, for example, mixing method, spray coating method, flow coating method, shower coating method, roll coating method, brush coating method and the like can be provided as a coating method. The thickness of the coating film after curing and drying is usually 0.05 to 400 µm, preferably 1 to 200 µm.

In order to control the coating film thickness, the composition of the present invention can be used diluted with a solvent. When used as a coating, for example, the composition typically has a viscosity of 0.1 to 50,000 mPa · s / 25 ° C., preferably 0.5 to 10,000 mPa · s / 25 ° C.

4. How to Cure the Composition

The composition of the present invention is cured by radiation (light).

There is no specific restriction on the light source of radiation as long as the composition after coating can be cured in a short time. As an example of the infrared light source, a lamp, a heat resistant plate, a laser and the like are provided. As an example of a light source of visible light, sunlight, a lamp, a fluorescent lamp, a laser, or the like may be provided. As a light source of ultraviolet rays, a mercury lamp, a halide lamp, a laser, or the like can be provided. Examples of light sources for electron beams include systems using thermoelectrons made from commercially available tungsten filaments, cold cathode methods for generating electron beams by passing high voltage pulses through metal, ionization A secondary electron method may be provided that uses second electrons generated by the collision of gas molecules and metal electrodes. α-ray, β-ray and γ-ray, for example Co ⁶⁰ , may be provided as a light source as a fissile material. The radiation can be used individually or in combination of two or more. In the latter case, two or more radiations may be used simultaneously or at specific intervals.

II. Curing products

The cured product of the present invention can be obtained by adding a composition on a plastic substrate and curing the coating. In particular the cured product can be obtained as a coated form by applying the composition on an object, drying the coating to preferably remove the volatile components at temperatures between 0 and 200 ° C. and curing the coating by radiation. have. As the radiation, ultraviolet rays and electron beams are preferable. The ultraviolet light is preferably irradiated at an irradiation amount of 0.01-10 J / cm 2, more preferably 0.1 to 2 J / cm 2. The electron beam is irradiated under the conditions of 10-300 KV, electron density of 0.02-0.30 mA / cm 2 and irradiation dose of 1-10 Mrad.

The refractive index of the cured product is preferably 1.69 or more, more preferably 1.71 or more.

Since the cured product of the present invention has excellent properties such as high hardness and high refractive index, the product is an artificial material used as a plastic optical component, a touch panel, a film-like liquid crystal component, a plastic container, or a flooring, a wall material and a building interior finishing material. As a protective coating to prevent stains or scratches in marble; It is suitable for use as an adhesive for various substrates, sealants and excipients for printing inks and the like.

The invention is illustrated in detail by the examples, which do not limit the invention.

In the following, "parts" and "%" are "parts by weight" and "wt%" unless stated otherwise.

In the present invention, the term "solid content" means the content of the components excluding volatile components such as solvents from the composition in the present invention, in particular "solid content" is obtained by drying the composition for 1 hour in a hot plate at 120 ℃ Means the content of water (non-volatile components).

Dispersion of Oxide Particles (A1) in an Organic Solvent

Dispersion example 1

300 parts by weight of zirconia powder (manufactured by Sumitomo Osaka Cement Co., Ltd.) is added to 700 parts by weight of methyl ethyl ketone (MEK) and dispersed for 168 hours using glass beads. The glass beads were removed and 950 parts by weight of zirconia dispersion sol (A1-1) in methyl ethyl ketone was obtained. 2 g of the dispersion is weighed in an aluminum dish and dried for 1 hour on a hotplate at 120 ° C. By weighing the dried material, the solids content is 30%. The specific surface area of the solid material measured by the BET method is 30 m ² / g, and the calculated particle diameter is 31 nm.

Dispersion example 2

MIBK zirconia sol (A1-2) is prepared by the same method as dispersion example 1 except using methyl isobutyl ketone (MIBK) instead of MEK. The content of the solid component in the dispersion is measured in the same manner as in dispersion example 1, the solid content is 30%. The specific surface area of the solid material measured by the BET method is 30 m ² / g, and the calculated particle diameter is 31 nm.

Dispersion example 3

Toluene zirconia sol (A1-3) is prepared in the same manner as in dispersion example 1 except that toluene is used instead of MEK. The content of the solid component in the dispersion is measured in the same manner as in dispersion example 1, the solid content is 30%. The specific surface area of the solid material measured by the BET method is 30 m ² / g, and the calculated particle diameter is 31 nm.

Synthesis of Organic Compound (A2)

Synthesis Example 1

20.6 parts of isophorone diisocyanate are added to a solution of 7.8 parts of mercaptopropyltrimethoxysilane and 0.2 parts of dibutyl tin dilaurate in dry air in one hour with stirring at 50 ° C. The mixture is stirred at 60 ° C. for an additional 3 hours. 71.4 parts of pentaerythritol triacrylate was added dropwise within 1 hour at 30 ° C., and the mixture was stirred for an additional 3 hours at 60 ° C. while heating to obtain an organic compound (A2-1). The amount of isocyanate remaining in the product is analyzed and the amount remaining is 0.1% or less, indicating that the reaction is almost quantitatively completed.

Preparation of Reactive Particles (A)

Preparation examples of the reactive particles (A) are disclosed in Preparation Examples 1 and 2. The results are summarized in Table 1.

Preparation Example 1

A mixture of 8.2 parts of the organic compound (A2-1) synthesized in Synthesis Example 1, 91.8 parts of MEK zirconia sol (A1-1), 41.2 parts of MEK and 0.1 part of ion-exchanged water was stirred at 60 ° C. for 3 hours. After 1 part of methyl ortho-formate is added, the mixture is stirred for an additional 1 hour at the same temperature to give a dispersion sol (A-1) of reactive particles (A). 2 g of are weighed on an aluminum dish and dried for 1 hour on a hotplate at 120 ° C. The dried material is weighed and has a solids content of 25%.

Preparation Example 2

Dispersion sol (A-2) of reactive particles (A) is prepared in the same manner as in dispersion example 1 except that toluene is used in place of MEK, and toluene zirconia sol is used. The content of the solid component in the dispersion sol (A-2) was measured in the same manner as in Preparation Example 1, and the solid content was 25%.

Production Example One 2 Dispersion Sol of Reactive Particles (A) A-1 A-2 Oxide Particle Sol (A1) A1-1 (oxide concentration: 30%) 91.8 - A1-3 (oxide concentration: 30%) - 91.8 Organic compound (A2) A2-1 8.2 8.2 Ion exchange water 0.1 0.1 menstruum Methyl ethyl ketone 41.2 - toluene - 41.2 Methyl ortho-formate 1.3 1.3 Solid content (%) 25 25 % Of oxide particles in solid components 77 77

Preparation of Composition

Examples of the preparation of the compositions of the present invention are disclosed in Examples 1-8 and Comparative Examples 1-2. The weight ratios of the components to the composition are shown in Table 2.

Example 1

A mixture of 267 parts of dispersion sol (A1-1) (80 parts of zirconia particles and 187 parts of dispersion medium MEK) and 20 parts of dipentaerythritol hexaacrylate was stirred at 50 ° C. for 2 hours to obtain a homogeneous liquid composition. To obtain. The solids content of the composition is measured in the same manner as in Preparation Example 1, the solids content is 35%.

Example 2-8

The composition of Examples 2-8 is prepared in the same manner as in Example 1, except that the ingredients disclosed in Table 2 are used.

Comparative Example 1

267 parts of dispersion sol (A1-1) (80 parts of zirconia particles and 187 parts of dispersion medium MEK), 20 parts of dipentaerythritol hexaacrylate, 1.5 parts and 1, of 1-hydroxycyclohexyl phenyl ketone, A mixture of 3.5 parts of 2-diethoxy acetophenone is stirred at 50 ° C. for 2 hours to obtain a homogeneous liquid composition. The solids content of the composition is measured in the same manner as in Preparation Example 1, the solids content is 36%.

Comparative Example 2-3

The composition of Comparative Example 2-3 is prepared in the same manner as in Example 1 except using the components disclosed in Table 2.

Evaluation of Curing Products

In order to demonstrate the effectiveness of the compositions of the invention, the cured products obtained from the above-mentioned compositions by coating, drying and radiation exposure are evaluated. The cured product is evaluated in the following manner. The evaluation results are shown in Table 2.

Assessment Methods

* Pencil Hardness:

The composition was added to a glass substrate using a bar coater to prepare a dry film having a thickness of 10 μm, dried for 3 minutes on a hot plate at 80 ° C., and at a dose of 1 J / cm 2 using a conveyor mercury lamp. Irradiation yields a cured coating. The cured coating was left at 25 ° C. for 24 hours and evaluated according to JIS K5400.

* Refractive Index:

A mixture of 100 parts of dipentaerythritol hexaacrylate or pentaerythritol triacrylate, 2 parts of hydroxycyclohexyl phenyl ketone and 187 parts of MEK is coated on the glass substrate described above, dried and dried under the conditions described above. Cures. After peeling off the glass substrate, the refractive index of the coated film was measured using an Abbe refractometer, and the refractive index of each mixture (mixture using dipentaerythritol hexaacrylate or pentaerythritol triacrylate) was 1.53.

Using the measured refractive index, the refractive index of the cured product of the present invention is calculated according to the following equation:

Refractive index of cured product = (refractive index of zirconia (2.05) x volume fraction of zirconia) + (refractive index of compound (B) (1.53) x volume fraction of compound (B))

A zirconia density of 5.49 g / cm 3 and a density of compound (B) of 1.19 g / cm 3 are used for the calculation of the volume fraction.

* Lamp pollution resistance:

The composition is added to a polyethylene terephthalate (PET) film substrate having a thickness of 188 μm using a bar coater to produce a 10 μm thick dry coating material. The coating is dried in an oven at 80 ° C. for 3 minutes, placed in a well sealed box with a top surface of 1 cm high made of quartz, and irradiated with light at a dose of 1 J / cm 2 using a conveyor-type mercury lamp. After curing, the blur of the stone is visually observed and the lamp contamination resistance is evaluated. Specimens without quartz clouding are of AAA grade, and if a slight clouding of quartz is observed, it is of BBB grade, and if the quartz is clouded, it is rated CCC.

In Table 2, an asterisk (*) for the oxide particles (A1), the reactive particles (A), and the silica particles (AS) represents the weight of the particles added in each dispersion sol (excluding organic solvents).

In Table 2, abbreviations have the following meanings.

AS-1: methyl ethyl ketone silica sol (solid content: 30%, MEK-ST manufactured by Nissan Chemical Industries, Ltd.)

C1: dipentaerythritol hexaacrylate

B2: pentaerythritol triacrylate

R1: 1-hydroxycyclohexyl phenyl ketone

R2: α, α-diethoxyacetophenone

Effects of the Invention

As described above, the present invention exhibits excellent coating properties, as well as photocurable compositions capable of forming coating materials having high hardness and high refractive index with high productivity without being affected by contamination of the lamp. It provides a cured product prepared from the composition.

Claims (6)

(A1) zirconium oxide particles or composite oxide particles containing zirconium and other metals, (B) A photocurable composition comprising a compound having two or more polymerizable unsaturated groups in a molecule, The composition is a photocurable composition, characterized in that substantially free of photo-radical polymerization initiator. (A) (A1) zirconium oxide particles or composite oxide particles containing zirconium and particles prepared by combining (A2) an organic compound having a polymerizable unsaturated group, (B) A photocurable composition comprising a compound having two or more polymerizable unsaturated groups in a molecule, The composition is a photocurable composition, characterized in that substantially free of photo-radical polymerization initiator. The method according to claim 1 or 2, The said component (B) is dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and ditrimethyl At least one compound selected from the group consisting of all propane tetra (meth) acrylate. The method according to any one of claims 1 to 3, (C) The photocurable composition further contains an organic solvent. A cured product prepared by curing the photocurable composition according to any one of claims 1 to 4. The method of claim 5, A cured product having a refractive index of at least 1.69.